This invention relates generally to optical correlation systems and, more particularly, to an optical correlator and method of correlation which are capable of providing rapid and reliable optical signal processing.
Optical correlators are extremely useful in the processing of optical signals in, for example, the analysis of radar information or sonar information. More specifically, the optical correlator can effectively compare a pair of optical input signals and by an analysis of intensity peaks determine information with respect to the optical input signals. A major problem in two dimensional optical signal processing by means of current optical correlators is the lack of rapid read-out of output signals during the optical correlation procedure. For example, the result of a joint transform optical correlator may very well yield a correlation peak located somewhere in a 10.sup.3 .times.10.sup.3 array of possible locations and it may be required to determine the exact location in the order of one microsecond. In addition, since there are generally a large number of smaller secondary intensity peaks associated with this output, it is not only necessary to determine which peak is the largest, but also the exact location of this largest intensity peak.
Conventional optical correlators incorporate therein a plurality of intensity detector arrays which provide information with respect to each of the intensity peaks in order to determine which, in fact, is the largest and where the largest intensity peaks are located. Unfortunately, during use in analyzing of radar or sonar information, current optical correlators are generally incapable of handling large amounts of data in a rapid and reliable fashion. It is therefore highly desirable to provide an optical correlator which is capable of handling large amounts of data and in doing so in a minimal amount of time.